Dexamethasone rapidly induces a novel ras superfamily member-related gene in AtT-20 cells.
Differential display was used to identify a new Ras superfamily gene (Dexras1) induced by dexamethasone (Dex) in AtT-20 cells. Treatment of AtT-20 cells with Dex for 30 min resulted in increased mRNA for Dexras1; the highest concentrations appeared after 2 h of treatment. The gene was also identified in mouse heart, brain, liver, and kidney and furthermore was induced in these tissues after Dex treatment. The deduced protein shows regions of homology characteristic of members of the Ras superfamily of small GTPases. Highest homology (36% identity, 57% positives) was found with human Rap-2b, followed closely by a number of other Ras subfamily members, suggesting that Dexras1 is probably a member of the Ras subfamily of GTPases (members include Ras and Rap). Dexras1 is the first Ras superfamily member identified that is induced in response to steroids. The function of this gene is unknown; however, its wide distribution and rapid induction by Dex suggests the possibility of a role in glucocorticoid action in a variety of tissues.
Kemppainen
R J
RJ
Department of Physiology and Pharmacology, Auburn University College of Veterinary Medicine, Auburn, Alabama 36849, USA. kempprj@vetmed.auburn.edu
Behrend
E N
EN
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002460:Cell Line; D003907:Dexamethasone / Q000494:pharmacology*; D020558:GTP Phosphohydrolases / Q000235:genetics*; D019204:GTP-Binding Proteins; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins; D012333:RNA, Messenger / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D018631:ras Proteins
C400132:RASD1 protein, human; D012333:RNA, Messenger; D003907:Dexamethasone; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; C498511:Rasd1 protein, mouse; D020559:Monomeric GTP-Binding Proteins; D018631:ras Proteins